Yeah.. i have the same problem with ke loops, but, my rudd elevator mix is really close.. I am fighting the roll coupling. Sounds like your rudder mod completely eliminated the roll coupling for the ke loop. I would like to try it, but, I don't really know where to begin. How close is it in fixing roll coupling to just remove the top part of the rudder? Did the taper really do that much or was it mostly removing the top?